The Rosy Rustic. 
81 
POTATO PESTS. 
The Rosy Rustic ( Ilydrcecia micaceci) attacking 
Potatoes. 
Amongst the numerous enemies from which the potato crop 
suffered during 1902 were the larvse of one of the noctuid moths 
known as the Rosy Rustic ( Hydrcccia micaceci). This attack was 
reported to the Board of Agriculture from two localities, namely from 
Winton, Manchester, and from near Wigan, Lancashire, and was also 
observed personally. The two notes sent with these larvae were as 
follows : — 
(1) Enclosed are grubs that have attacked and are destroying a large 
patch of potatoes ; will you kindly say what they are and what remedy I 
can take. 
(2) I herewith send two insects that I have found amongst my 
potatoes. They were looking well to about a week ago. Any information 
about them will be thankfully received. 
In both cases the caterpillars were found to be working in a 
similar way, namely, by tunnelling up the stalks of the potatoes, 
completely hollowing them out and so killing the haulm. Should 
this pest become very numerous it would be a serious matter, as 
remedies are quite out of the question save hand-picking the 
attacked haulm. These caterpillars are recorded as feeding in the 
stems of equisetums, docks, valerian, but probably attack a variety 
of other plants. 
The larva when mature varies from an inch and a quarter to an 
inch and a half in length. The back and sides are dull purplish- 
brown, paler on the first three segments and where the segments 
join, the sides and venter are of a dull flesh colour, the legs pale and 
the head yellowish-brown ; on the second segment is a brown semi- 
circular plate broadly margined in front with blackish-brown and a 
shiny yellowish-brown patch on the anal segment with a posterior 
border of small dark warts ; on the segments are small dark -brown 
tubercular warts each with a fine terminal hair ; the spiracles are 
deep brown and the prolegs pale with black extremities. 
Before pupation the larva becomes a paler dull smoky flesh 
colour all over, with a dusky median dorsal line. The full-fed stage 
is reached from the beginning to the end of July. During the whole 
of its life the larva burrows up the haulm and emits a great quantity 
of green frass ; a round exit hole is made in the stem, the frass being 
G 
